types: Annotate the AST visitors

7 files changed, 93 insertions, 90 deletions

diff --git a/mesonbuild/ast/interpreter.py b/mesonbuild/ast/interpreter.py
index 09d8d32..e2f4e12 100644
--- a/mesonbuild/ast/interpreter.py
+++ b/mesonbuild/ast/interpreter.py
@@ -190,7 +190,7 @@ class AstInterpreter(interpreterbase.InterpreterBase):
             self.assignments[node.var_name] = []
             self.assign_vals[node.var_name] = []
         self.assignments[node.var_name] += [node.value] # Save a reference to the value node
-        if hasattr(node.value, 'ast_id'):
+        if node.value.ast_id:
             self.reverse_assignment[node.value.ast_id] = node
         self.assign_vals[node.var_name] += [self.evaluate_statement(node.value)]
 
@@ -250,7 +250,7 @@ class AstInterpreter(interpreterbase.InterpreterBase):
     def assignment(self, node):
         assert(isinstance(node, AssignmentNode))
         self.assignments[node.var_name] = [node.value] # Save a reference to the value node
-        if hasattr(node.value, 'ast_id'):
+        if node.value.ast_id:
             self.reverse_assignment[node.value.ast_id] = node
         self.assign_vals[node.var_name] = [self.evaluate_statement(node.value)] # Evaluate the value just in case
 
@@ -274,7 +274,7 @@ class AstInterpreter(interpreterbase.InterpreterBase):
         if not isinstance(node, BaseNode):
             return None
 
-        assert(hasattr(node, 'ast_id'))
+        assert node.ast_id
         if node.ast_id in id_loop_detect:
             return None # Loop detected
         id_loop_detect += [node.ast_id]
diff --git a/mesonbuild/ast/introspection.py b/mesonbuild/ast/introspection.py
index 709dbac..b191be3 100644
--- a/mesonbuild/ast/introspection.py
+++ b/mesonbuild/ast/introspection.py
@@ -145,7 +145,6 @@ class IntrospectionInterpreter(AstInterpreter):
         version = kwargs.get('version', [])
         if not isinstance(version, list):
             version = [version]
-        condition_level = node.condition_level if hasattr(node, 'condition_level') else 0
         if isinstance(required, ElementaryNode):
             required = required.value
         if not isinstance(required, bool):
@@ -155,8 +154,8 @@ class IntrospectionInterpreter(AstInterpreter):
             'required': required,
             'version': version,
             'has_fallback': has_fallback,
-            'conditional': condition_level > 0,
-            'node': node,
+            'conditional': node.condition_level > 0,
+            'node': node
         }]
 
     def build_target(self, node, args, kwargs, targetclass):
diff --git a/mesonbuild/ast/postprocess.py b/mesonbuild/ast/postprocess.py
index 8e8732f..aa19916 100644
--- a/mesonbuild/ast/postprocess.py
+++ b/mesonbuild/ast/postprocess.py
@@ -17,48 +17,49 @@
 
 from . import AstVisitor
 from .. import mparser
+from typing import Dict
 
 class AstIndentationGenerator(AstVisitor):
-    def __init__(self):
+    def __init__(self) -> None:
         self.level = 0
 
-    def visit_default_func(self, node: mparser.BaseNode):
+    def visit_default_func(self, node: mparser.BaseNode) -> None:
         # Store the current level in the node
         node.level = self.level
 
-    def visit_ArrayNode(self, node: mparser.ArrayNode):
+    def visit_ArrayNode(self, node: mparser.ArrayNode) -> None:
         self.visit_default_func(node)
         self.level += 1
         node.args.accept(self)
         self.level -= 1
 
-    def visit_DictNode(self, node: mparser.DictNode):
+    def visit_DictNode(self, node: mparser.DictNode) -> None:
         self.visit_default_func(node)
         self.level += 1
         node.args.accept(self)
         self.level -= 1
 
-    def visit_MethodNode(self, node: mparser.MethodNode):
+    def visit_MethodNode(self, node: mparser.MethodNode) -> None:
         self.visit_default_func(node)
         node.source_object.accept(self)
         self.level += 1
         node.args.accept(self)
         self.level -= 1
 
-    def visit_FunctionNode(self, node: mparser.FunctionNode):
+    def visit_FunctionNode(self, node: mparser.FunctionNode) -> None:
         self.visit_default_func(node)
         self.level += 1
         node.args.accept(self)
         self.level -= 1
 
-    def visit_ForeachClauseNode(self, node: mparser.ForeachClauseNode):
+    def visit_ForeachClauseNode(self, node: mparser.ForeachClauseNode) -> None:
         self.visit_default_func(node)
         self.level += 1
         node.items.accept(self)
         node.block.accept(self)
         self.level -= 1
 
-    def visit_IfClauseNode(self, node: mparser.IfClauseNode):
+    def visit_IfClauseNode(self, node: mparser.IfClauseNode) -> None:
         self.visit_default_func(node)
         for i in node.ifs:
             i.accept(self)
@@ -67,7 +68,7 @@ class AstIndentationGenerator(AstVisitor):
             node.elseblock.accept(self)
             self.level -= 1
 
-    def visit_IfNode(self, node: mparser.IfNode):
+    def visit_IfNode(self, node: mparser.IfNode) -> None:
         self.visit_default_func(node)
         self.level += 1
         node.condition.accept(self)
@@ -75,10 +76,10 @@ class AstIndentationGenerator(AstVisitor):
         self.level -= 1
 
 class AstIDGenerator(AstVisitor):
-    def __init__(self):
-        self.counter = {}
+    def __init__(self) -> None:
+        self.counter = {}  # type: Dict[str, int]
 
-    def visit_default_func(self, node: mparser.BaseNode):
+    def visit_default_func(self, node: mparser.BaseNode) -> None:
         name = type(node).__name__
         if name not in self.counter:
             self.counter[name] = 0
@@ -86,20 +87,20 @@ class AstIDGenerator(AstVisitor):
         self.counter[name] += 1
 
 class AstConditionLevel(AstVisitor):
-    def __init__(self):
+    def __init__(self) -> None:
         self.condition_level = 0
 
-    def visit_default_func(self, node: mparser.BaseNode):
+    def visit_default_func(self, node: mparser.BaseNode) -> None:
         node.condition_level = self.condition_level
 
-    def visit_ForeachClauseNode(self, node: mparser.ForeachClauseNode):
+    def visit_ForeachClauseNode(self, node: mparser.ForeachClauseNode) -> None:
         self.visit_default_func(node)
         self.condition_level += 1
         node.items.accept(self)
         node.block.accept(self)
         self.condition_level -= 1
 
-    def visit_IfClauseNode(self, node: mparser.IfClauseNode):
+    def visit_IfClauseNode(self, node: mparser.IfClauseNode) -> None:
         self.visit_default_func(node)
         for i in node.ifs:
             i.accept(self)
@@ -108,7 +109,7 @@ class AstConditionLevel(AstVisitor):
             node.elseblock.accept(self)
             self.condition_level -= 1
 
-    def visit_IfNode(self, node: mparser.IfNode):
+    def visit_IfNode(self, node: mparser.IfNode) -> None:
         self.visit_default_func(node)
         self.condition_level += 1
         node.condition.accept(self)
diff --git a/mesonbuild/ast/printer.py b/mesonbuild/ast/printer.py
index 033b1d5..06f3c62 100644
--- a/mesonbuild/ast/printer.py
+++ b/mesonbuild/ast/printer.py
@@ -28,7 +28,7 @@ arithmic_map = {
 }
 
 class AstPrinter(AstVisitor):
-    def __init__(self, indent: int = 2, arg_newline_cutoff: int = 5):
+    def __init__(self, indent: int = 2, arg_newline_cutoff: int = 5) -> None:
         self.result = ''
         self.indent = indent
         self.arg_newline_cutoff = arg_newline_cutoff
@@ -36,113 +36,110 @@ class AstPrinter(AstVisitor):
         self.is_newline = True
         self.last_level = 0
 
-    def post_process(self):
+    def post_process(self) -> None:
         self.result = re.sub(r'\s+\n', '\n', self.result)
 
-    def append(self, data: str, node: mparser.BaseNode):
-        level = 0
-        if node and hasattr(node, 'level'):
-            level = node.level
-        else:
-            level = self.last_level
-        self.last_level = level
+    def append(self, data: str, node: mparser.BaseNode) -> None:
+        self.last_level = node.level
         if self.is_newline:
-            self.result += ' ' * (level * self.indent)
+            self.result += ' ' * (node.level * self.indent)
         self.result += data
         self.is_newline = False
 
-    def append_padded(self, data: str, node: mparser.BaseNode):
+    def append_padded(self, data: str, node: mparser.BaseNode) -> None:
         if self.result[-1] not in [' ', '\n']:
             data = ' ' + data
         self.append(data + ' ', node)
 
-    def newline(self):
+    def newline(self) -> None:
         self.result += '\n'
         self.is_newline = True
 
-    def visit_BooleanNode(self, node: mparser.BooleanNode):
+    def visit_BooleanNode(self, node: mparser.BooleanNode) -> None:
         self.append('true' if node.value else 'false', node)
 
-    def visit_IdNode(self, node: mparser.IdNode):
+    def visit_IdNode(self, node: mparser.IdNode) -> None:
+        assert isinstance(node.value, str)
         self.append(node.value, node)
 
-    def visit_NumberNode(self, node: mparser.NumberNode):
+    def visit_NumberNode(self, node: mparser.NumberNode) -> None:
         self.append(str(node.value), node)
 
-    def visit_StringNode(self, node: mparser.StringNode):
+    def visit_StringNode(self, node: mparser.StringNode) -> None:
+        assert isinstance(node.value, str)
         self.append("'" + node.value + "'", node)
 
-    def visit_ContinueNode(self, node: mparser.ContinueNode):
+    def visit_ContinueNode(self, node: mparser.ContinueNode) -> None:
         self.append('continue', node)
 
-    def visit_BreakNode(self, node: mparser.BreakNode):
+    def visit_BreakNode(self, node: mparser.BreakNode) -> None:
         self.append('break', node)
 
-    def visit_ArrayNode(self, node: mparser.ArrayNode):
+    def visit_ArrayNode(self, node: mparser.ArrayNode) -> None:
         self.append('[', node)
         node.args.accept(self)
         self.append(']', node)
 
-    def visit_DictNode(self, node: mparser.DictNode):
+    def visit_DictNode(self, node: mparser.DictNode) -> None:
         self.append('{', node)
         node.args.accept(self)
         self.append('}', node)
 
-    def visit_OrNode(self, node: mparser.OrNode):
+    def visit_OrNode(self, node: mparser.OrNode) -> None:
         node.left.accept(self)
         self.append_padded('or', node)
         node.right.accept(self)
 
-    def visit_AndNode(self, node: mparser.AndNode):
+    def visit_AndNode(self, node: mparser.AndNode) -> None:
         node.left.accept(self)
         self.append_padded('and', node)
         node.right.accept(self)
 
-    def visit_ComparisonNode(self, node: mparser.ComparisonNode):
+    def visit_ComparisonNode(self, node: mparser.ComparisonNode) -> None:
         node.left.accept(self)
         self.append_padded(node.ctype, node)
         node.right.accept(self)
 
-    def visit_ArithmeticNode(self, node: mparser.ArithmeticNode):
+    def visit_ArithmeticNode(self, node: mparser.ArithmeticNode) -> None:
         node.left.accept(self)
         self.append_padded(arithmic_map[node.operation], node)
         node.right.accept(self)
 
-    def visit_NotNode(self, node: mparser.NotNode):
+    def visit_NotNode(self, node: mparser.NotNode) -> None:
         self.append_padded('not', node)
         node.value.accept(self)
 
-    def visit_CodeBlockNode(self, node: mparser.CodeBlockNode):
+    def visit_CodeBlockNode(self, node: mparser.CodeBlockNode) -> None:
         for i in node.lines:
             i.accept(self)
             self.newline()
 
-    def visit_IndexNode(self, node: mparser.IndexNode):
+    def visit_IndexNode(self, node: mparser.IndexNode) -> None:
         node.iobject.accept(self)
         self.append('[', node)
         node.index.accept(self)
         self.append(']', node)
 
-    def visit_MethodNode(self, node: mparser.MethodNode):
+    def visit_MethodNode(self, node: mparser.MethodNode) -> None:
         node.source_object.accept(self)
         self.append('.' + node.name + '(', node)
         node.args.accept(self)
         self.append(')', node)
 
-    def visit_FunctionNode(self, node: mparser.FunctionNode):
+    def visit_FunctionNode(self, node: mparser.FunctionNode) -> None:
         self.append(node.func_name + '(', node)
         node.args.accept(self)
         self.append(')', node)
 
-    def visit_AssignmentNode(self, node: mparser.AssignmentNode):
+    def visit_AssignmentNode(self, node: mparser.AssignmentNode) -> None:
         self.append(node.var_name + ' = ', node)
         node.value.accept(self)
 
-    def visit_PlusAssignmentNode(self, node: mparser.PlusAssignmentNode):
+    def visit_PlusAssignmentNode(self, node: mparser.PlusAssignmentNode) -> None:
         self.append(node.var_name + ' += ', node)
         node.value.accept(self)
 
-    def visit_ForeachClauseNode(self, node: mparser.ForeachClauseNode):
+    def visit_ForeachClauseNode(self, node: mparser.ForeachClauseNode) -> None:
         varnames = [x for x in node.varnames]
         self.append_padded('foreach', node)
         self.append_padded(', '.join(varnames), node)
@@ -152,7 +149,7 @@ class AstPrinter(AstVisitor):
         node.block.accept(self)
         self.append('endforeach', node)
 
-    def visit_IfClauseNode(self, node: mparser.IfClauseNode):
+    def visit_IfClauseNode(self, node: mparser.IfClauseNode) -> None:
         prefix = ''
         for i in node.ifs:
             self.append_padded(prefix + 'if', node)
@@ -163,23 +160,23 @@ class AstPrinter(AstVisitor):
             node.elseblock.accept(self)
         self.append('endif', node)
 
-    def visit_UMinusNode(self, node: mparser.UMinusNode):
+    def visit_UMinusNode(self, node: mparser.UMinusNode) -> None:
         self.append_padded('-', node)
         node.value.accept(self)
 
-    def visit_IfNode(self, node: mparser.IfNode):
+    def visit_IfNode(self, node: mparser.IfNode) -> None:
         node.condition.accept(self)
         self.newline()
         node.block.accept(self)
 
-    def visit_TernaryNode(self, node: mparser.TernaryNode):
+    def visit_TernaryNode(self, node: mparser.TernaryNode) -> None:
         node.condition.accept(self)
         self.append_padded('?', node)
         node.trueblock.accept(self)
         self.append_padded(':', node)
         node.falseblock.accept(self)
 
-    def visit_ArgumentNode(self, node: mparser.ArgumentNode):
+    def visit_ArgumentNode(self, node: mparser.ArgumentNode) -> None:
         break_args = (len(node.arguments) + len(node.kwargs)) > self.arg_newline_cutoff
         for i in node.arguments + list(node.kwargs.values()):
             if not isinstance(i, (mparser.ElementaryNode, mparser.IndexNode)):
diff --git a/mesonbuild/ast/visitor.py b/mesonbuild/ast/visitor.py
index de13dae..ec51014 100644
--- a/mesonbuild/ast/visitor.py
+++ b/mesonbuild/ast/visitor.py
@@ -18,122 +18,123 @@
 from .. import mparser
 
 class AstVisitor:
-    def __init__(self):
+    def __init__(self) -> None:
         pass
 
-    def visit_default_func(self, node: mparser.BaseNode):
+    def visit_default_func(self, node: mparser.BaseNode) -> None:
         pass
 
-    def visit_BooleanNode(self, node: mparser.BooleanNode):
+    def visit_BooleanNode(self, node: mparser.BooleanNode) -> None:
         self.visit_default_func(node)
 
-    def visit_IdNode(self, node: mparser.IdNode):
+    def visit_IdNode(self, node: mparser.IdNode) -> None:
         self.visit_default_func(node)
 
-    def visit_NumberNode(self, node: mparser.NumberNode):
+    def visit_NumberNode(self, node: mparser.NumberNode) -> None:
         self.visit_default_func(node)
 
-    def visit_StringNode(self, node: mparser.StringNode):
+    def visit_StringNode(self, node: mparser.StringNode) -> None:
         self.visit_default_func(node)
 
-    def visit_ContinueNode(self, node: mparser.ContinueNode):
+    def visit_ContinueNode(self, node: mparser.ContinueNode) -> None:
         self.visit_default_func(node)
 
-    def visit_BreakNode(self, node: mparser.BreakNode):
+    def visit_BreakNode(self, node: mparser.BreakNode) -> None:
         self.visit_default_func(node)
 
-    def visit_ArrayNode(self, node: mparser.ArrayNode):
+    def visit_ArrayNode(self, node: mparser.ArrayNode) -> None:
         self.visit_default_func(node)
         node.args.accept(self)
 
-    def visit_DictNode(self, node: mparser.DictNode):
+    def visit_DictNode(self, node: mparser.DictNode) -> None:
         self.visit_default_func(node)
         node.args.accept(self)
 
-    def visit_EmptyNode(self, node: mparser.EmptyNode):
+    def visit_EmptyNode(self, node: mparser.EmptyNode) -> None:
         self.visit_default_func(node)
 
-    def visit_OrNode(self, node: mparser.OrNode):
+    def visit_OrNode(self, node: mparser.OrNode) -> None:
         self.visit_default_func(node)
         node.left.accept(self)
         node.right.accept(self)
 
-    def visit_AndNode(self, node: mparser.AndNode):
+    def visit_AndNode(self, node: mparser.AndNode) -> None:
         self.visit_default_func(node)
         node.left.accept(self)
         node.right.accept(self)
 
-    def visit_ComparisonNode(self, node: mparser.ComparisonNode):
+    def visit_ComparisonNode(self, node: mparser.ComparisonNode) -> None:
         self.visit_default_func(node)
         node.left.accept(self)
         node.right.accept(self)
 
-    def visit_ArithmeticNode(self, node: mparser.ArithmeticNode):
+    def visit_ArithmeticNode(self, node: mparser.ArithmeticNode) -> None:
         self.visit_default_func(node)
         node.left.accept(self)
         node.right.accept(self)
 
-    def visit_NotNode(self, node: mparser.NotNode):
+    def visit_NotNode(self, node: mparser.NotNode) -> None:
         self.visit_default_func(node)
         node.value.accept(self)
 
-    def visit_CodeBlockNode(self, node: mparser.CodeBlockNode):
+    def visit_CodeBlockNode(self, node: mparser.CodeBlockNode) -> None:
         self.visit_default_func(node)
         for i in node.lines:
             i.accept(self)
 
-    def visit_IndexNode(self, node: mparser.IndexNode):
+    def visit_IndexNode(self, node: mparser.IndexNode) -> None:
         self.visit_default_func(node)
         node.iobject.accept(self)
         node.index.accept(self)
 
-    def visit_MethodNode(self, node: mparser.MethodNode):
+    def visit_MethodNode(self, node: mparser.MethodNode) -> None:
         self.visit_default_func(node)
         node.source_object.accept(self)
         node.args.accept(self)
 
-    def visit_FunctionNode(self, node: mparser.FunctionNode):
+    def visit_FunctionNode(self, node: mparser.FunctionNode) -> None:
         self.visit_default_func(node)
         node.args.accept(self)
 
-    def visit_AssignmentNode(self, node: mparser.AssignmentNode):
+    def visit_AssignmentNode(self, node: mparser.AssignmentNode) -> None:
         self.visit_default_func(node)
         node.value.accept(self)
 
-    def visit_PlusAssignmentNode(self, node: mparser.PlusAssignmentNode):
+    def visit_PlusAssignmentNode(self, node: mparser.PlusAssignmentNode) -> None:
         self.visit_default_func(node)
         node.value.accept(self)
 
-    def visit_ForeachClauseNode(self, node: mparser.ForeachClauseNode):
+    def visit_ForeachClauseNode(self, node: mparser.ForeachClauseNode) -> None:
         self.visit_default_func(node)
         node.items.accept(self)
         node.block.accept(self)
 
-    def visit_IfClauseNode(self, node: mparser.IfClauseNode):
+    def visit_IfClauseNode(self, node: mparser.IfClauseNode) -> None:
         self.visit_default_func(node)
         for i in node.ifs:
             i.accept(self)
         if node.elseblock:
             node.elseblock.accept(self)
 
-    def visit_UMinusNode(self, node: mparser.UMinusNode):
+    def visit_UMinusNode(self, node: mparser.UMinusNode) -> None:
         self.visit_default_func(node)
         node.value.accept(self)
 
-    def visit_IfNode(self, node: mparser.IfNode):
+    def visit_IfNode(self, node: mparser.IfNode) -> None:
         self.visit_default_func(node)
         node.condition.accept(self)
         node.block.accept(self)
 
-    def visit_TernaryNode(self, node: mparser.TernaryNode):
+    def visit_TernaryNode(self, node: mparser.TernaryNode) -> None:
         self.visit_default_func(node)
         node.condition.accept(self)
         node.trueblock.accept(self)
         node.falseblock.accept(self)
 
-    def visit_ArgumentNode(self, node: mparser.ArgumentNode):
+    def visit_ArgumentNode(self, node: mparser.ArgumentNode) -> None:
         self.visit_default_func(node)
         for i in node.arguments:
             i.accept(self)
-        for val in node.kwargs.values():
+        for key, val in node.kwargs.items():
+            key.accept(self)
             val.accept(self)
diff --git a/mesonbuild/mparser.py b/mesonbuild/mparser.py
index 84b686e..ad871f0 100644
--- a/mesonbuild/mparser.py
+++ b/mesonbuild/mparser.py
@@ -232,6 +232,11 @@ class BaseNode:
         self.end_lineno = end_lineno if end_lineno is not None else self.lineno
         self.end_colno = end_colno if end_colno is not None else self.colno
 
+        # Attributes for the visitors
+        self.level = 0            # type: int
+        self.ast_id = ''          # type: str
+        self.condition_level = 0  # type: int
+
     def accept(self, visitor: 'AstVisitor') -> None:
         fname = 'visit_{}'.format(type(self).__name__)
         if hasattr(visitor, fname):
diff --git a/mesonbuild/rewriter.py b/mesonbuild/rewriter.py
index 6aaa269..a6d2256 100644
--- a/mesonbuild/rewriter.py
+++ b/mesonbuild/rewriter.py
@@ -593,7 +593,7 @@ class Rewriter:
             self.modefied_nodes += [node]
 
     def find_assignment_node(self, node: BaseNode) -> AssignmentNode:
-        if hasattr(node, 'ast_id') and node.ast_id in self.interpreter.reverse_assignment:
+        if node.ast_id and node.ast_id in self.interpreter.reverse_assignment:
             return self.interpreter.reverse_assignment[node.ast_id]
         return None